This invention relates to amplifying arrangements employing klystrons or like devices and more particularly, but not exclusively, to such arrangements comprising television transmitters.
In a television transmitter, typically a klystron amplifies a radio frequency carrier, which has been modulated with either a video signal, or with video or sound signals simultaneously, the latter mode of operation being known as a "multiplexed" mode.
A "klystron" is a device for amplifying high frequency signals. A typical klystron comprises an electron gun section and an interaction region. The electron gun section includes a cathode at which electrons are emitted in a beam, and a beam controlling electrode which controls the magnitude of the electron beam current. The interaction region comprises a cavity at which the high frequency signal to be amplified velocity modulates the electrons of the beam, and typically comprises several cavities, the amplified signal being taken from the final one.
The present invention seeks to provide an improved klystron arrangement.